Welcome to the London attraction of the week – the formidable, information-packed, royal wedding tour of London. Available, with slight variations, through half a dozen different companies, but always, inevitably, featuring such highlights as where Prince William went out dancing (and ran up a bar tab of £11,000 – about $18,000) after he broke it off with Kate for a few months.

But let's not dwell on unhappy memories. With the nuptials of William and Kate only four days away, the city is filling up with tourists – and journalists – from across the globe, all eager to see, hear about, and feel some of the magic of the royal love story.

“In the next 2-1/2 hours we'll be discussing the highs and lows of William and Kate’s relationship,” begins Hana Umezawa, the charming guide from Celebrity Planet tours, as she gets the afternoon started peering into the window of the jewelry store where Princess Diana’s blue sapphire and diamond engagement ring – now adorning Kate's slender finger – was purchased.

Two dozen tourists and almost as many journalists soon are paused in front of Jigsaw for a moment of philosophical reflection.

“Kate’s struggle to hold down a job since graduating reportedly earned the displeasure of the Queen,” intones Ms. Umezawa – who has a master's in international development but moonlights on the wedding beat – looking solemn.

“I understand how she feels, that queen,” nods Don Savant, a young man from Trinidad who flew 10 hours to be part of the festivities in London this week. “Work is an important ethic. Even for royals.”

The tour zips by Mahikis, the Polynesian-themed tiki bar club where William came to drown his sorrows after the 2007 breakup, reportedly jumping up on a table and yelling "I’m free!” It then heads over to Clarence House, where Prince Charles and the Duchess of Cornwall currently live, and continues on to Buckingham Palace, now surrounded with massive stages for the world media to be able to capture the big Friday afternoon kiss on the balcony.

The questions come fast and furious. “Do you know anything about the cake details?” ask David and Adele Bywaters, from Cornwall – who plan to bake a cake on the wedding day and have a party themselves. “Why did William break up with Kate over the phone?” the concerned Australian asks.

The tour winds through the parks, alongside the royal homes and the royal shoemakers, and ends, finally, at Westminster Abbey, first built in the 11th century by the Anglo-Saxon King Edward the Confessor, and famed place of royal coronations, burials, and weddings. On Friday at 11 a.m., Kate will step out of a Rolls Royce in her wedding dress, for the whole world to see, and step into this church to become a princess.

Outside the abbey, the very first of the diehard royal enthusiasts are beginning to pitch their tents and lay down sleeping bags, so as to get the best view on the day. Mr. Savant, intrigued, strikes up a chat with John Loughrey, a former assistant chef dressed in a T-shirt stating, “Diana would be proud.”

A PR woman from a mattress company comes up with an inflatable mattress and a pump – a gift. That’s it – Savant is sold. He will stay right here, he tells Mr. Loughrey, and seats himself between him and Guen Murray, a mother of four who has arrived with a suitcase and a large ball of wool so she can knit as she waits out the week.

She was also there 30 years ago, says Ms. Murray, camping outside Buckingham Palace for the wedding of Diana to Prince Charles. She would not miss this one for the world. “Me neither,” exclaims Savant, happy to find a likeminded soul, and sharing his granola bar with his new friends. “This is history. This is the modern day fairy tale.”

[Editor's note:The original version of this story misstated the age of Westminster Abbey.]